Let us define a regular brackets sequence in the following way:1. Empty sequence is a regular sequence.2. If S is a regular sequence, then (S) and [S] are both regular sequences.3. If A and B are regular sequences, then AB is a regular sequence.For example, all of the following sequences of characters are regular brackets sequences:(), [], (()), ([]), ()[], ()[()]And all of the following character sequences are not:(, [, ), )(, ([)], ([(]Some sequence of characters ‘(‘, ‘)’, ‘[‘, and ‘]’ is given. You are to find the shortest possible regular brackets sequence, that contains the given character sequence as a subsequence. Here, a string a1 a2 … an is called a subsequence of the string b1 b2 … bm, if there exist such indices 1 = i1 < i2 < … < in = m, that aj = bij for all 1 = j = n.
，的这一半更多地赢取上帝掌握的那一半。
